Recent leveling off of vegetation greenness and primary production reveals the increasing soil water limitations on the greening Earth

2021 ◽  
Author(s):  
Xiaoming Feng ◽  
Bojie Fu ◽  
Yuan Zhang ◽  
Naiqing Pan ◽  
Zhenzhong Zeng ◽  
...  
Keyword(s):  
Primary Production ◽  
Soil Water ◽  
Vegetation Greenness ◽  
Water Limitations

scholarly journals Global joint assimilation of GRACE and SMOS for improved estimation of root-zone soil moisture and vegetation response

2018 ◽  
Author(s):  
Siyuan Tian ◽  
Luigi J. Renzullo ◽  
Albert I. J. M. van Dijk ◽  
Paul Tregoning ◽  
Jeffrey P. Walker
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Soil Water ◽  
Root Zone ◽  
Water Storage ◽  
Microwave Remote Sensing ◽  
Open Loop ◽  
Total Water ◽  
Vegetation Response ◽  
Vegetation Greenness

Abstract. The lack of direct measurement of root-zone soil moisture poses a challenge to the large-scale prediction of ecosystem response to variation in soil water. Microwave remote sensing capability is limited to measuring moisture content in the uppermost few centimetres of soil. In contrast, GRACE (Gravity Recovery and Climate Experiment) mission detected the variability in storage within the total water column, which is often dominated by groundwater variation. However, not all vegetation communities can access groundwater. In this study, satellite-derived water content from GRACE and SMOS were jointly assimilated into an ecohydrological model to better predict the impact of changes in root-zone soil moisture on vegetation vigour. Overall, the accuracy of root-zone soil moisture prediction though the joint assimilation of surface soil moisture and total water storage retrievals showed improved consistency with ground-based soil moisture measurements and satellite-observed greenness when compared to open-loop estimates (i.e. without assimilation). For example, the correlation between modelled and in-situ measurements of root-zone moisture increased by 0.1 on average over grasslands and croplands. Improved correlations were found between vegetation greenness and soil water storage derived from the joint assimilation with an increase up to 0.47 over grassland compared to open-loop estimates. Joint assimilation results show a more severe deficit in soil water in eastern Australia, western North America and eastern Brazil over the period of 2010 to 2015 than the open-loop, consistent with the satellite-observed vegetation greenness. The assimilation of satellite-observed water content contributes to more accurate knowledge of soil water availability, providing new insights for monitoring hidden water stress and vegetation response.

Application of composted pig bedding litter on a Vertosol and Sodosol soil. 1. Effect on crop growth and soil water

2007 ◽  
Vol 47 (6) ◽  
pp. 689 ◽  
Author(s):  
R. D. Armstrong ◽  
C. Eagle ◽  
V. Matassa ◽  
S. D. Jarwal
Keyword(s):  
Wheat Straw ◽  
Soil Water ◽  
Clay Soil ◽  
Crop Growth ◽  
Yield Potential ◽  
Nitrogen Fertiliser ◽  
Rice Hulls ◽  
Beneficial Effects ◽  
Matter Production ◽  
Water Limitations

Trials were undertaken at two sites with contrasting soil types in the Wimmera region of Victoria: a well-structured grey cracking clay soil (Vertosol) at Traynors Lagoon and a poorly structured sodic clay soil (Sodosol) at Gre Gre. The effect of a once-off application of three different types of bedding litter (wheat straw and two types of rice hulls) applied at three rates (20, 30 and 40 t/ha) was compared with that of a control (no amelioration), nitrogen fertiliser (46 kg N/ha) applied to each crop, or nitrogen plus a once-off application of gypsum (2.5 t/ha). The growth of three subsequent crops and soil water was examined. Pig bedding litter (rice hulls 1, rice hulls 2 or wheat straw) produced marked improvements in the dry matter production and grain yield of the first crop (wheat) in 1997 and a following canola crop in 1998. In 1999, bedding litter significantly improved the growth of an oats crop at Gre Gre, but had no effect on a crop of field peas at Traynors Lagoon. The beneficial effects of bedding litter on grain yields, however, were matched by small but significant reductions in grain quality resulting from soil water limitations for the yield potential. Although crop growth was improved by the addition of nitrogen fertiliser each year or both nitrogen plus gypsum, the effect was usually small compared with that of adding litter and provided minimal residual value in the following year. There was a general trend for gravimetric soil water to be higher at sowing where bedding litter had been applied, especially at Gre Gre. In contrast, soil water tended to be lower at grain maturity at Traynors Lagoon, where bedding litter or nitrogen fertiliser had been applied, reflecting the enhanced crop growth in these treatments compared with the control. There was no consistent effect of treatments on soil water at maturity in either 1998 or 1999 at Gre Gre.

scholarly journals Large and projected strengthening moisture limitation on end-of-season photosynthesis

2020 ◽  
Vol 117 (17) ◽  
pp. 9216-9222 ◽  
Author(s):  
Yao Zhang ◽  
Nicholas C. Parazoo ◽  
A. Park Williams ◽  
Sha Zhou ◽  
Pierre Gentine
Keyword(s):  
Soil Water ◽  
Growing Season ◽  
Energy Availability ◽  
Wet Season ◽  
Late Season ◽  
Vegetation Activity ◽  
Future Warming ◽  
Water Limitations ◽  
Using Data ◽  
Underlying Mechanisms

Terrestrial photosynthesis is regulated by plant phenology and environmental conditions, both of which experienced substantial changes in recent decades. Unlike early-season photosynthesis, which is mostly driven by temperature or wet-season onset, late-season photosynthesis can be limited by several factors and the underlying mechanisms are less understood. Here, we analyze the temperature and water limitations on the ending date of photosynthesis (EOP), using data from both remote-sensing and flux tower-based measurements. We find a contrasting spatial pattern of temperature and water limitations on EOP. The threshold separating these is determined by the balance between energy availability and soil water supply. This coordinated temperature and moisture regulation can be explained by “law of minimum,” i.e., as temperature limitation diminishes, higher soil water is needed to support increased vegetation activity, especially during the late growing season. Models project future warming and drying, especially during late season, both of which should further expand the water-limited regions, causing large variations and potential decreases in photosynthesis.

scholarly journals A New Wetness Index to Evaluate the Soil Water Availability Influence on Gross Primary Production of European Forests

Climate ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 42 ◽  
Author(s):  
Chiara Proietti ◽  
Alessandro Anav ◽  
Marcello Vitale ◽  
Silvano Fares ◽  
Maria Francesca Fornasier ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Primary Production ◽  
Soil Water ◽  
Water Availability ◽  
Tree Species ◽  
Gross Primary Production ◽  
Soil Water Availability ◽  
Arid Environments ◽  
Site Location ◽  
Wetness Index

Rising temperature, drought and more-frequent extreme climatic events have been predicted for the next decades in many regions around the globe. In this framework, soil water availability plays a pivotal role in affecting vegetation productivity, especially in arid or semi-arid environments. However, direct measurements of soil moisture are scarce, and modeling estimations are still subject to biases. Further investigation on the effect of soil moisture on plant productivity is required. This study aims at analyzing spatio-temporal variations of a modified temperature vegetation wetness index (mTVWI), a proxy of soil moisture, and evaluating its effect on gross primary production (GPP) in forests. The study was carried out in Europe on 19 representative tree species during the 2000–2010 time period. Results outline a north–south gradient of mTVWI with minimum values (low soil water availability) in Southern Europe and maximum values (high soil water availability) in Northeastern Europe. A low soil water availability negatively affected GPP from 20 to 80%, as a function of site location, tree species, and weather conditions. Such a wetness index improves our understanding of water stress impacts, which is crucial for predicting the response of forest carbon cycling to drought and aridity.

scholarly journals Global joint assimilation of GRACE and SMOS for improved estimation of root-zone soil moisture and vegetation response

2019 ◽  
Vol 23 (2) ◽  
pp. 1067-1081 ◽  
Author(s):  
Siyuan Tian ◽  
Luigi J. Renzullo ◽  
Albert I. J. M. van Dijk ◽  
Paul Tregoning ◽  
Jeffrey P. Walker
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Surface Soil ◽  
Root Zone ◽  
Water Storage ◽  
Microwave Remote Sensing ◽  
Open Loop ◽  
Total Water ◽  
Surface Soil Moisture ◽  
Vegetation Greenness

Abstract. The lack of direct measurement of root-zone soil moisture poses a challenge to the large-scale prediction of ecosystem response to variation in soil water. Microwave remote sensing capability is limited to measuring moisture content in the uppermost few centimetres of soil. The GRACE (Gravity Recovery and Climate Experiment) mission detected the variability in storage within the total water column. However, root-zone soil moisture cannot be separated from GRACE-observed total water storage anomalies without ancillary information on surface water and groundwater changes. In this study, GRACE total water storage anomalies and SMOS near-surface soil moisture observations were jointly assimilated into a hydrological model globally to better estimate the impact of changes in root-zone soil moisture on vegetation vigour. Overall, the accuracy of root-zone soil moisture estimates through the joint assimilation of surface soil moisture and total water storage retrievals showed improved consistency with ground-based soil moisture measurements and satellite-observed greenness when compared to open-loop estimates (i.e. without assimilation). For example, the correlation between modelled and in situ measurements of root-zone moisture increased by 0.1 (from 0.48 to 0.58) and 0.12 (from 0.53 to 0.65) on average for grasslands and croplands, respectively. Improved correlations were found between vegetation greenness and soil water storage on both seasonal variability and anomalies over water-limited regions. Joint assimilation results show a more severe deficit in soil water anomalies in eastern Australia, southern India and eastern Brazil over the period of 2010 to 2016 than the open-loop, consistent with the satellite-observed vegetation greenness anomalies. The assimilation of satellite-observed water content contributes to more accurate knowledge of soil water availability, providing new insights for monitoring hidden water stress and vegetation conditions.

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